Excimer laser-induced vasoreactivity.

Earlier generations of excimer lasers, designed for industrial or non-cardiovascular medical applications, have been previously shown consistently to induce vasorelaxation of vascular smooth muscle in vitro. Such lasers were typically characterized by pulse durations of < or = 15 nanoseconds (ns). Excimer lasers currently employed for cardiovascular applications were designed with longer pulse durations (up to 220 ns) to facilitate fibreoptic transmission.

Quantitative relationship between liquid bolus flow and laryngeal closure during deglutition.

We employed digital image analysis to assess the relative movements of the hyoid, larynx, and bolus as a function of liquid bolus volume (2-15 ml), and synchronized these measurements with intrapharyngeal manometry. Comparisons were performed of bolus head and tail movement in relation to the timing of hyoid movement, contact between the arytenoid and epiglottic cartilages, and intrabolus pressures. Bolus head movement in the distal pharynx, as determined from flow plots, was relatively rapid.

Neuropeptide FF receptors: structure-activity relationship and effect of morphine.

Neuropeptide FF (FLFQPQRFamide, NPFF) is an octapeptide implicated in morphine analgesia, tolerance and dependence. Many of the behavioral effects of NPFF have also been observed with the invertebrate neuropeptide Phe-Met-Arg-Phe-amide (FMRFamide), which binds to NPFF receptors because of its low homology to the C-terminal portion of NPFF. A competitive ligand binding assay was used to characterize NPFF receptors in rat spinal cord and a strong requirement was found for the C-terminal Arg-Phe-amide.

Molecular basis of spectrin deficiency in hereditary pyropoikilocytosis.

Hereditary pyropoikilocytosis (HPP) is a recessively inherited hemolytic anemia characterized by severe poikilocytosis and red blood cell fragmentation. HPP red blood cells are partially deficient in spectrin and contain a mutant alpha or beta-spectrin that is defective in terms of spectrin self-association. Although the nature of the latter defect has been studied in considerable detail and many mutations of alpha-spectrin and beta spectrin have been identified, the molecular basis of spectrin deficiency is unknown.

Seronegative, non-neoplastic acute cerebellar degeneration.

Five women are presented with a subacute pure pancerebellar syndrome of ataxia and dysarthria to emphasize that this illness may occur without anti-Purkinje-cell or anti-Yo antibodies, or associated systemic cancer. The syndrome evolved over weeks or less and stabilized in four of the patients. Three had had a preceding infection and one, a rash, but there was no inflammatory response in the spinal fluid.

Syndrome of transtentorial herniation: is vertical displacement necessary?

MRI from a comatose patient with a massive acute subdural haematoma showed most of the features of transtentorial herniation described in the classic pathology literature. In addition to encroachment on the perimesencephalic cisterns, infarction in the anterior and posterior cerebral artery territories, ischaemic change in the lower diencephalon, and ventricular enlargement were visualised. Despite the clinical syndrome and these secondary changes due to compression, there was only approximately 2 mm of downward displacement of the upper brainstem compared with 13 mm horizontal displacement.

Inhibition of endothelium-dependent vasorelaxation by sickle erythrocytes.

Interactions between erythrocytes and vascular endothelium have been implicated in the pathogenesis of vaso-occlusion in sickle cell anemia. Sickle erythrocytes adhere to endothelial cells and facilitate trapping of rigid sickle cells in microvessels. Compensatory dilation of precapillary arterioles may mitigate the occlusion.

Cloning of human erythroid dematin reveals another member of the villin family.

Dematin is an actin-bundling protein originally identified in the human erythroid membrane skeleton. Its actin-bundling activity is abolished upon phosphorylation by the cAMP-dependent protein kinase and is restored after dephosphorylation. Here we report the complete primary structure of human erythroid dematin, whose sequence includes a homologue of the "headpiece" sequence found at the C terminus of villin.

In vitro evidence that myocardial ischemia resulting from 5-fluorouracil chemotherapy is due to protein kinase C-mediated vasoconstriction of vascular smooth muscle.

5-Fluorouracil (5-FU) is a commonly employed chemotherapeutic agent. Among the various toxicities associated with 5-FU, cardiovascular toxicity, consisting principally of acute myocardial ischemia and/or myocardial infarction, has been reported in up to 8.5% of patients treated with this drug.

Limitations of color flow Doppler imaging in the quantification of valvular regurgitation: velocity of regurgitant jet, rather than volume, determines size of color Doppler image.

The objective of this study was to determine the validity of estimation of regurgitant volume by visual assessment of color flow Doppler display. An experimental apparatus was designed that is capable of ejecting precise volumes of echogenic material from one chamber to another under continuous color flow Doppler monitoring. The velocity of flow was altered independently by changing either the size of the orifice through which flow occurred or the ejection rate.

Combined physiologic and anatomic assessment of percutaneous revascularization using a Doppler guidewire and ultrasound catheter.

Previous investigations have established the utility of intravascular ultrasound (IVUS) examination for the evaluation of arterial dimensions and qualitative changes following percutaneous revascularization. More recently, the feasibility of obtaining intravascular physiology findings before and/or after percutaneous revascularization by use of an intravascular Doppler Flowire (Cardiometrics) has been demonstrated. Accordingly, we investigated the feasibility of using this combined physiologic/anatomic approach to evaluate individuals undergoing percutaneous revascularization of stenotic or occluded coronary and peripheral arteries.

Structural domain mapping and phosphorylation of human erythrocyte pallidin (band 4.2).

Pallidin (band 4.2) is a major protein of the human erythrocyte membrane, and plays an important but as yet undefined role in maintaining the normal shape and lifespan of the erythrocyte. The pallidin protein has been purified by a new procedure which yields a protein which is > 97% pure as judged by gel electrophoresis, while pallidin purified by our original procedure is only approx.

Human immune globulin infusion in Guillain-Barré syndrome: worsening during and after treatment.

Because of an unexpectedly high rate of worsening, we report the results of treatment of Guillain-Barré syndrome with a standard regimen of human immune globulin (HIG) in 15 consecutive patients. Patients were treated with 1.5 g/kg HIG for 4 days beginning a mean of 7 days after the first symptoms.

Accelerated neuropathy of renal failure.

Objective: To describe a syndrome of rapidly evolving polyneuropathy in patients with severe renal failure.

Design: Retrospective case series of four patients.

Setting: In-hospital evaluations and personal examinations of patients.

Modulation of neuropeptide FF receptors by guanine nucleotides and cations in membranes of rat brain and spinal cord.

Using a radioligand binding assay, we examined ionic modulation and G protein coupling of neuropeptide FF (NPFF) receptors in membranes of rat brain and spinal cord. We found that NaCl (but not KCl or LiCl) and MgCl2 increased specific 125I-YLFQPQRFamide (125I-Y8Fa) binding to NPFF receptors in both tissues in a dose-dependent manner, with optimal conditions being 60 mM NaCl and 1 mM MgCl2. Guanine nucleotides dose-dependently inhibited specific 125I-Y8Fa binding to rat brain and spinal cord membranes with maximal effects of 64 +/- 6 and 71 +/- 2%, respectively.

Biogenesis of erythrocyte membrane skeleton in health and disease.

To study the biogenesis of red cell membrane skeleton at various stages of erythroid differentiation, we have chosen the following model systems: a) Rauscher erythroleukemia cell line representing the early stages of differentiation, b) Friend erythroleukemia cells, and c) in vitro cultured human erythroblasts. The latter two systems represent terminally differentiated erythroblasts. Using these model systems, we have shown asynchronous synthesis of membrane proteins during erythroid differentiation.

Sudden death in idiopathic dilated cardiomyopathy: role of ventricular arrhythmias.

Sudden cardiac death (SCD) is associated with idiopathic congestive cardiomyopathy (IDCM) and most commonly is due to ventricular tachyarrhythmias. The recurrence rate of SCD in the absence of specific therapy is thought to be around 20%-30% per year. Asymptomatic and symptomatic ventricular arrhythmias are common in patients with IDCM and the direct causal link of such arrhythmias with SCD in IDCM patients remains to be established.

Characterization of a transmissible growth-promoting agent derived from CSF of schizophrenic patients which is active on human neuroblastoma cells.

A growth-promoting agent for the human neuroblastoma cell line SK-N-SH(EP) (SH-EP) has been detected in human cerebrospinal fluid (CSF) derived from schizophrenic patients. Following treatment with the CSF, a number of properties of the SH-EP cells changed permanently. These included an accelerated rate of growth, an increased cell density at confluence, a change of cell shape, and an increased ability to form colonies in soft agar.

Proliferative activity in peripheral and coronary atherosclerotic plaque among patients undergoing percutaneous revascularization.

We evaluated the proliferative activity of human atherosclerotic lesions associated with active symptoms of ischemia, by assessing the expression of the proliferating cell nuclear antigen (PCNA). We confirmed in vitro that PCNA, an essential component of the DNA synthesis machinery, is selectively expressed in proliferating human vascular smooth muscle cells. 37 atherosclerotic lesions (18 primary and 19 restenotic) retrieved by directional atherectomy from either coronary or peripheral arteries were then studied for the expression of PCNA, using in situ hybridization or immunohistochemistry.

Handedness in twins with schizophrenia: was Boklage correct?

Boklage's report of increased non-right handedness among monozygotic twins with schizophrenia has been cited as evidence to support an association of abnormal brain lateralization with the development of schizophrenia. The present study found no such association. Two previous attempts to replicate Boklage's findings (Luchins et al.